Japan has taken another step toward hypersonic passenger travel after researchers completed a successful ground combustion test of a ramjet engine designed for a Mach 5 aircraft.
The test was carried out by the Japan Aerospace Exploration Agency in partnership with Waseda University, the University of Tokyo, and Keio University. It was conducted at JAXA’s Kakuda Space Center and simulated flight at five times the speed of sound.
The project could eventually support aircraft capable of flying from Tokyo to Los Angeles in about two hours.
How The Ramjet Engine Works
A ramjet is an air-breathing jet engine with no moving parts.
It works by using the aircraft’s forward speed to force air into the engine, compress it, mix it with fuel, and ignite it to produce thrust.
Because ramjets do not need heavy rotating compressors, they can operate at speeds far beyond conventional turbofan engines. However, they cannot start from a standstill and must first be accelerated to supersonic speeds.
Extreme Heat Was A Main Test Focus
During the Japanese test, engineers mounted an experimental aircraft model inside a wind tunnel that simulated conditions at around 25 kilometers above Earth.
At that altitude, the atmosphere is roughly one hundredth as dense as it is at sea level.
At Mach 5, the air around the nose and leading edges of an aircraft can exceed 1,000 degrees Celsius. That level of heat creates one of the biggest challenges for hypersonic aircraft, and it has also been a major issue for US Air Force hypersonic jet programs.
To manage the heat, engineers used an advanced thermal protection system. The system kept the aircraft’s interior near normal operating temperature so its avionics and control electronics could continue working.
Sensors also mapped surface temperature distribution to check thermal structure calculations. These results will be important if the design is scaled up for a full-size passenger aircraft.
Next Step Is A Flight Test
The latest test does not mean a hypersonic passenger jet is ready to fly.
It was a ground-based test using a scaled-down model. JAXA’s next step is to mount the experimental vehicle on a sounding rocket and attempt an actual Mach 5 flight.
A sounding rocket is a suborbital rocket used for scientific experiments and measurements in space.
If future testing succeeds and technical and regulatory challenges are solved, Japan is targeting commercial hypersonic passenger service by the 2040s.
Two-hour Pacific Flights Remain the Long-term Goal
A Mach 5 aircraft flying at an altitude of 25 kilometers could theoretically cut the Tokyo to Los Angeles journey from about 10 hours to roughly two hours.
That altitude is nearly double the height reached by current commercial airliners.
The aircraft would not need to enter full orbit, but it could still reduce long-distance travel times sharply. A trip between the US and Japan could change from a long international flight into a same-day journey with only a few hours in the air.
No it can’t and no it won’t.
The reason is that it would Cause alot of issues. We had hypersonic aircrafts before . It was called concord. It was Mach 2 speed and caused alot of issues for everyone
1. Jetlag
2. At Mach 2 it could shatter windows of it flew over houses or residential areas.
3. It was extremely expensive and required alot of maintainance.
4. It consumed fuel. Like alot of it.
Now multiply all these for a Mach 5 aircraft.
Doesn’t sound good does it
Why so negative? Never underestimate technological advances and human ingenuity. Just look at how fast robot technology is progressing now.